Total Dissolved Solids (TDS) is the objective scientific measure of strength. The ristretto is technically as STRONG as the normale.

The problem is with the definition the request. When a customer ask for a WEAK coffee they could be asking for

Less caffeine

Less bitterness

A lighter roast

More watery flavour

We don’t know what they want when they ask for weak. The customer doesn’t know what they want. Are they asking for less coffee in their coffee? Perhaps. However that won’t achieve any of the above outcomes. In fact a ristretto will achieve the opposite of the above in most cases.

As baristas and owners in the coffee community we have to move away from subjective coffee.

I prescribe using a fixed recipe for a balanced espresso and pouring out half the shot – after mixing – to create a “weak” coffee. That way the balanced full espresso that is extracted evenly will be mixed and when you pour out half you will have half the amount of a great espresso rather than the first part of a bad espresso.